Glass Studio

p. 843-847The Institute for Lightweight Structures and Conceptual Design has for many years been actively engaged in the research and development of advanced glass structures and systems, including long-span glass arches, adhesively-constructed glass domes, switchable glazing elements, and reinforced glass. In the summer semester of 2008 the institute held an interdisciplinary workshop for students from the faculties of Civil Engineering and Architecture, with technical guidance provided by the glass fabrication shop at the Stuttgart State Academy of Art and Design. During the workshop new possibilities were explored in the use of glass as a material. The students gained insight into the theoretical foundations of glass while simultaneously accumulating practical experience working with the material. Different fabrication approaches and technologies were used to create glass objects which reveal new design qualities beyond the aspect of transparency. During the studio, lamination techniques were used to embed optical fibres between two glass panes, generating three-dimensional light images; glass rod structures were created with smooth, pure glass joints achieved through local heating; horizontal slats of glass were layered vertically to achieve a visual superposition of direct and reflected views; glass shards were fused at different temperatures to generate sharp-edged and fragile, or smoothedged and sturdy objects; different thermal treatments were applied to produce flexible glass hybrid materials combining metal wires and glass shards, or slumped glass panes which recall the design vocabulary of lightweight structures. A detailed description of the different techniques employed and the various objects created follows in this article.Puller, K.; Heinz, P.; Frettlöhr, B.; Sobek, W. (2010). Glass Studio. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/695

Dynamic Visual Attention: competitive versus motion priority scheme

Defined as attentive process in presence of visual sequences, dynamic visual attention responds to static and motion features as well. For a computer model, a straightforward way to integrate these features is to combine all features in a competitive scheme: the saliency map contains a contribution of each feature, static and motion. Another way of integration is to combine the features in a motion priority scheme: in presence of motion, the saliency map is computed as the motion map, and in absence of motion, as the static map. In this paper, four models are considered: two models based on a competitive scheme and two models based on a motion priority scheme. The models are evaluated experimentally by comparing them with respect to the eye movement patterns of human subjects, while viewing a set of video sequences. Qualitative and quantitative evaluations, performed in the context of simple synthetic video sequences, show the highest performance of the motion priority scheme, compared to the competitive scheme

Local Support Assembly of the ATLAS Pixel Detector

The barrel part of the ATLAS pixel detector will consist of 112 carbon-carbon structures called "staves" with 13 hybrid detector modules being glued on each stave. The demands on the glue joints are high, both in terms of mechanical precision and thermal contact. To achieve this precision a custom-made semi-automated mounting machine has been constructed in Wuppertal, which provides a precision in the order of tens of microns. As this is the last stage of the detector assembly providing an opportunity for stringent tests, a detailed procedure has been defined for assessing both mechanical and electrical properties. This note gives an overview of the procedure for affixation and tests, and summarizes the first results of the production.Comment: 6 pages, 8 figure

Equity Markets and the Performance of Hedge Funds: How stable is Persistence?

We investigate the performance of hedge funds inbull and bear equity markets. Covering the period from January1994 to December 2008, we find that each bull and bear marketperiod has its dominant independent variables. Furthermore, thelevel of performance persistence is not significantly related toequity market conditions. The analyses show that hedge fundperformance persistence is stronger in more recent sub-periodsthan in earlier sub-periods. In bullish as well as in bearish equitymarkets, performance persistence is driven by both constantwinners and losers. Moreover, both live and dead funds exhibitstatistically significant levels of performance persistence

Time resolved X-ray Dark-Field Tomography Revealing Water Transport in a Fresh Cement Sample

Grating-based X-ray dark-field tomography is a promising technique for biomedical and materials research. Even if the resolution of conventional X-ray tomography does not suffice to resolve relevant structures, the dark-field signal provides valuable information about the sub-pixel microstructural properties of the sample. Here, we report on the potential of X-ray dark-field imaging to be used for time-resolved three-dimensional studies. By repeating consecutive tomography scans on a fresh cement sample, we were able to study the hardening dynamics of the cement paste in three dimensions over time. The hardening of the cement was accompanied by a strong decrease in the dark-field signal pointing to microstructural changes within the cement paste. Furthermore our results hint at the transport of water from certain limestone grains, which were embedded in the sample, to the cement paste during the process of hardening. This is indicated by an increasing scattering signal which was observed for two of the six tested limestone grains. Electron microscopy images revealed a distinct porous structure only for those two grains which supports the following interpretation of our results. When the water filled pores of the limestone grains empty during the experiment the scattering signal of the grains increases

An integrated cryogenic optical modulator

Integrated electrical and photonic circuits (PIC) operating at cryogenic temperatures are fundamental building blocks required to achieve scalable quantum computing, and cryogenic computing technologies. Optical interconnects offer better performance and thermal insulation than electrical wires and are imperative for true quantum communication. Silicon PICs have matured for room temperature applications but their cryogenic performance is limited by the absence of efficient low temperature electro-optic (EO) modulation. While detectors and lasers perform better at low temperature, cryogenic optical switching remains an unsolved challenge. Here we demonstrate EO switching and modulation from room temperature down to 4 K by using the Pockels effect in integrated barium titanate (BaTiO3)-based devices. We report the nonlinear optical (NLO) properties of BaTiO3 in a temperature range which has previously not been explored, showing an effective Pockels coefficient of 200 pm/V at 4 K. We demonstrate the largest EO bandwidth (30 GHz) of any cryogenic switch to date, ultra-low-power tuning which is 10^9 times more efficient than thermal tuning, and high-speed data modulation at 20 Gbps. Our results demonstrate a missing component for cryogenic PICs. It removes major roadblocks for the realisation of novel cryogenic-compatible systems in the field of quantum computing and supercomputing, and for interfacing those systems with the real world at room-temperature

Absolute proteomic quantification reveals design principles of sperm flagellar chemosensation

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Troetschel, C., Hamzeh, H., Alvarez, L., Pascal, R., Lavryk, F., Boenigk, W., Koerschen, H. G., Mueller, A., Poetsch, A., Rennhack, A., Gui, L., Nicastro, D., Struenker, T., Seifert, R., & Kaupp, U. B. Absolute proteomic quantification reveals design principles of sperm flagellar chemosensation. Embo Journal, 39(4), (2020): e102723, doi:10.15252/embj.2019102723.Cilia serve as cellular antennae that translate sensory information into physiological responses. In the sperm flagellum, a single chemoattractant molecule can trigger a Ca2+ rise that controls motility. The mechanisms underlying such ultra‐sensitivity are ill‐defined. Here, we determine by mass spectrometry the copy number of nineteen chemosensory signaling proteins in sperm flagella from the sea urchin Arbacia punctulata. Proteins are up to 1,000‐fold more abundant than the free cellular messengers cAMP, cGMP, H+, and Ca2+. Opto‐chemical techniques show that high protein concentrations kinetically compartmentalize the flagellum: Within milliseconds, cGMP is relayed from the receptor guanylate cyclase to a cGMP‐gated channel that serves as a perfect chemo‐electrical transducer. cGMP is rapidly hydrolyzed, possibly via “substrate channeling” from the channel to the phosphodiesterase PDE5. The channel/PDE5 tandem encodes cGMP turnover rates rather than concentrations. The rate‐detection mechanism allows continuous stimulus sampling over a wide dynamic range. The textbook notion of signal amplification—few enzyme molecules process many messenger molecules—does not hold for sperm flagella. Instead, high protein concentrations ascertain messenger detection. Similar mechanisms may occur in other small compartments like primary cilia or dendritic spines.We thank Heike Krause for preparing the manuscript. Financial support by the Deutsche Forschungsgemeinschaft (DFG) via the priority program SPP 1726 “Microswimmers” and the Cluster of Excellence 1023 “ImmunoSensation” is gratefully acknowledged. We thank D. Stoddard for management of the UTSW cryo‐electron microscope facility, which is funded in part by a Cancer Prevention and Research Institute of Texas (CPRIT) Core Facility Award (RP170644). This study was supported by HHS|National Institutes of Health (NIH) grant R01 GM083122 and by CPRIT grant RR140082 to D. Nicastro

Handgrip Strength Values Depend on Tumor Entity and Predict 180-Day Mortality in Malnourished Cancer Patients.

BACKGROUND Cancer-related malnutrition is a prevalent condition associated with a loss of muscle mass and impaired functional status, leading to immunodeficiency, impaired quality of life and adverse clinical outcomes. Handgrip strength (HGS) is a practical measure to assess muscle strength in individual patients during clinical practice. However, HGS reference values refer to populations of healthy people, and population-specific values, such as those in the population of cancer patients, still need to be defined. METHODS Within a secondary analysis of a previous randomized controlled nutritional trial focusing on hospitalized cancer patients at risk for malnutrition, we investigated sex-specific HGS values stratified by age and tumor entity. Additionally, we examined the association between HGS and 180-day all-cause mortality. RESULTS We included data from 628 cancer patients, which were collected from eight hospitals in Switzerland. Depending on the age of patients, HGS varied among female patients from 7 kg to 26 kg and among male patients from 20.5 kg to 44 kg. An incremental decrease in handgrip strength by 10 kg resulted in a 50% increase in 180-day all-cause mortality (odds ratio 1.52 (95%CI 1.19 to 1.94), p = 0.001). CONCLUSION Our data provide evidence of the prognostic implications of HGS measurement in cancer patients and validate the prognostic value of handgrip strength in regard to long-term mortality. In addition, our results provide expected HGS values in the population of hospitalized malnourished cancer patients, which may allow better interpretation of values in individual patients

Selective In Vivo and In Vitro Effects of a Small Molecule Inhibitor of Cyclin-Dependent Kinase 4

Background: Cyclin-dependent kinase 4 (Cdk4) represents a prime target for the treatment of cancer because most human cancers are characterized by overexpression of its activating partner cyclin D1, loss of the natural Cdk4-specific inhibitor p16, or mutation(s) in Cdk4's catalytic subunit. All of these can cause deregulated cell growth, resulting in tumor formation. We sought to identify a small molecule that could inhibit the kinase activity of Cdk4 in vitro and to then ascertain the effects of that inhibitor on cell growth and tumor volume in vivo. Methods: A triaminopyrimidine derivative, CINK4 (a chemical inhibitor of Cdk4), was identified by screening for compounds that could inhibit Cdk4 enzyme activity in vitro. Kinase assays were performed on diverse human Cdks and on other kinases that were expressed in and purified from insect cells to determine the specificity of CINK4. Cell cycle effects of CINK4 on tumor and normal cells were studied by flow cytometry, and changes in phosphorylation of the retinoblastoma protein (pRb), a substrate of Cdk4, were determined by western blotting. The effect of the inhibitor on tumor growth in vivo was studied by use of tumors established through xenografts of HCT116 colon carcinoma cells in mice. Statistical tests were two-sided. Results: CINK4 specifically inhibited Cdk4/cyclin D1 in vitro. It caused growth arrest in tumor cells and in normal cells and prevented pRb phosphorylation. CINK4 treatment resulted in statistically significantly (P = .031) smaller mean tumor volumes in a mouse xenograft model. Conclusions: Like p16, the natural inhibitor of Cdk4, CINK4 inhibits Cdk4 activity in vitro and slows tumor growth in vivo. The specificity of CINK4 for Cdk4 raises the possibility that this small molecule or one with a similar structure could have therapeutic valu

Siglec receptors impact mammalian lifespan by modulating oxidative stress.

Aging is a multifactorial process that includes the lifelong accumulation of molecular damage, leading to age-related frailty, disability and disease, and eventually death. In this study, we report evidence of a significant correlation between the number of genes encoding the immunomodulatory CD33-related sialic acid-binding immunoglobulin-like receptors (CD33rSiglecs) and maximum lifespan in mammals. In keeping with this, we show that mice lacking Siglec-E, the main member of the CD33rSiglec family, exhibit reduced survival. Removal of Siglec-E causes the development of exaggerated signs of aging at the molecular, structural, and cognitive level. We found that accelerated aging was related both to an unbalanced ROS metabolism, and to a secondary impairment in detoxification of reactive molecules, ultimately leading to increased damage to cellular DNA, proteins, and lipids. Taken together, our data suggest that CD33rSiglecs co-evolved in mammals to achieve a better management of oxidative stress during inflammation, which in turn reduces molecular damage and extends lifespan